COSMOS of Assembly

[BodyBagger]

I read in the help file that you can run Cosmos Express on an assembly only after running physical dynamics on the assy. I do not understand how I would run physical dynamics on a piece of plate steel that is resting on 4 edges of concrete (2" overlap) with no support in the middle. I need to simulate vehicle weight (resting) on the plate to check for the amount of plate deflection. Would I use the gravity option?

 

[polykracker]

According to our VAR we couldn't use COSMOSExpress on assemblies. You could use split lines to model the contact (fix) the 2" wide steel and apply a load over the wheel area and use cosmos express on just the part. Why not just use a formula from Roark's to get the deflection, assuming the plate is simple enough? ( thickness is not more that 1/4 of shortest side, and doesn't deflect more than 1/2 thickness). If you assume a concentrated load in the mid of the plate
Max Deflection = iWb^2/Et^3
where
a = longest side of plate
b = shortest side of plate

a/b 1.0 1.2 1.4 1.6 1.8 2.0 inf
i .1267 .1478 .1621 .1715 .1770 .1805 .1851

W = weight
E = mod of elasticity
t = thickness

Hope this helps

 

[BodyBagger]

polykracker - Thanks for the suggestion. However, we have a small sub-frame of tubing that is welded to the bottom of the plate to make it more rigid because there is no floor support in the middle. Unfortunately, I beleieve this takes the plate out of the "simple" category

 

[engAlright]

You could save the assembly as a part and run that through Cosmosexpress. Ensure that the plate is touching the supports before you save the assembly as a part, then save using the "All Components" check box from Save As within the assemblu.

You could then use split lines to create new model faces to which you can apply your restraints and loads.

 

[BodyBagger]

engAlright - I will give your suggestion a try. Thank You!